/*

public class ListNode {

int val;

ListNode next = null;

ListNode(int val) {

this.val = val;

}

}

*/

public class Solution {

public ListNode deleteDuplication(ListNode pHead)

{

//head为null

if(pHead==null)

return null;

if(pHead.next==null)

return pHead;

//临时的头结点

ListNode root=new ListNode(0);

root.next = pHead;

//记录前驱节点

ListNode prev = root;

//记录前驱节点

ListNode node = pHead;

while(node!=null&&node.next!=null)

{

//有重复节点，与node值相同的节点都要删除

if(node.val==node.next.val){

while(node.next!=null &&node.next.val==node.val)

{

node = node.next;

}

prev.next=node.next;

}

else{

prev.next= node;

prev=prev.next;

}

node=node.next;

}

return root.next;

}

}